Oregon Secretary of State Kate Brown wants to greatly expand Oregon's voter pool by automatically registering those who are eligible to vote.AP Photo/Jonathan J. Cooper

Oregon Secretary of State Kate Brown will present Oregon legislators with an ambitious plan Wednesday that would ensure that almost all eligible Oregonians are automatically registered to vote.

Brown plans to unveil legislation that would use driver-license data and -- eventually -- data from other government agencies to register citizens.

"I do not think that voter registration should be a barrier to participation in voting," Brown said in an interview Tuesday, "and our goal is to get ballots in the hands of every eligible Oregonian."

Brown's proposal could give Oregon the broadest pool of registered voters in the country – with the exception of North Dakota, which does not require voters to be registered.

Her legislation is certain to attract close scrutiny from lawmakers and political activists concerned about how it will affect the security of the voting system and whether it would give either political party an advantage.

"We need to take a hard look at it," said Greg Leo, executive director of the Oregon Republican Party, "but having more voters registered isn't necessarily a bad thing."

House Rules Chairman Chris Garrett, D-Lake Oswego, who will hold a hearing on Brown's proposal, said he expects a heated debate over the proposal. He noted that Republicans on his committee have already expressed opposition to a much milder voter registration bill that would allow 16-year-olds to register, although they still wouldn't be able to vote until they are 18.

Brown, a Democrat, insisted that she isn't seeking a partisan advantage and doesn't think moving toward universal registration would create one. She noted that Minnesota -- which in 2012 had the country's highest turnout of eligible voters -- has seen its top office see-saw back and forth between the major parties as well as former Reform Party Gov. Jesse Ventura.

Oregon's turnout rate last year of just under 83 percent of registered voters was one of the highest in the country, thanks in part to the state's pioneering system of vote-by-mail. But Brown said that Oregon is "what I'd call mediocre" in registering voters.

Unlike states that allow voters to register as late as Election Day, Oregon cuts off registration 20 days in advance of an election. All told, about 25 percent of Oregonians who are otherwise eligible to vote were not registered for the 2012 election.

Brian Shipley, the deputy secretary of state, said the state could get about 93 percent of eligible voters registered through the use of Oregon DMV data. The secretary of state is also working with the Department of Human Services, the Oregon Health Authority and other agencies to obtain data that could be used for registration.

Under the federal "motor voter" law of 1993, Oregon's DMV asks people obtaining a driver's license or ID card if they want a voter registration form. People changing their addresses online are offered a link to a form allowing them to update their voter registration.

Since 2008, Oregon applicants must provide evidence that they are legally in the country to get a driver's license. DMV spokesman David House said the agency also has data on whether new applicants are citizens, which is a requirement to vote.

Under Brown's proposal, which will be introduced as an amendment to House Bill 2198, eligible Oregonians would learn they had been registered using DMV data when they received a letter from the secretary of state.

The letter would explain how they could opt out of being registered to vote and how they could register under one of the political parties. Under the bill, they would be automatically registered as non-affiliated voters.

Michael McDonald, a political scientist at George Mason University in Virginia, said Canada created a similar system in the 1990s that produced near-universal registration. Still, actual voter turnout in that country continued to slide, he said, demonstrating that higher registration didn't counter a trend toward lower turnout.

However, McDonald, who has studied voter registration and turnout extensively, said it's possible that Brown's proposal could increase turnout. Unlike most states, Oregon mails a ballot to every registered voter, which makes voting easier. And the 20-day registration cutoff prevents some people from voting who only get interested in the last days of an election campaign.

If the bill passes, "it will be an interesting experiment in Oregon," said McDonald. "In some ways, we're in unique territory here."